Method and apparatus for vehicle control and guidance

ABSTRACT

A vehicle guidance and control system for providing information concerning the speed and direction of movement of a vehicle along a predetermined path on a roadway. The path is defined by a plurality of spaced, permanently magnetized elements located along the roadway. Vehicle mounted sensors respond to the magnetic fields of the elements and produce electrical signals representing the speed and direction of movement of the vehicle with respect to the path. In one embodiment, the electrical signals are employed as control signals in a closed loop electromechanical guidance system for the vehicle. By varying the pattern of magnetic polarization of the elements, binary information can be transferred from the roadway to the vehicle. With suitable data processing equipment in the vehicle, traffic information, such as, speed limits, directions, accident information, exit directions and the like can be visually presented to the vehicle operator.

Unite States Spaulding atent 51 June 6,1972

[21] Appl.No.: 878,407

Cronberger ..85/10 R Fayling ..340/32 Primary Examiner-Kathleen H.Claffy Assistant ExaminerRanda.ll P. Myers Att0rneyChittick, Pfund,Birch, Samuels & Gauthier [57] ABSTRACT A vehicle guidance and controlsystem for providing information concerning the speed and direction ofmovement of a vehicle along a predetermined path on a roadway. The pathis defined by a plurality of spaced, permanently magnetized elementslocated along the roadway. Vehicle mounted sensors respond to themagnetic fields of the elements and produce electrical signalsrepresenting the speed and direction of movement of the vehicle withrespect to the path. In one embodiment, the electrical signals areemployed as control signals in a closed loop electromechanical guidancesystem for the vehicle. By varying the pattern of magnetic polarizationof the elements, binary information can be transferred from the roadwayto the vehicle. With suitable data processing equipment in the vehicle,traffic information, such as, speed limits, directions, accidentinformation, exit directions and the like can be visually presented tothe vehicle operator.

9 Claims, 8 Drawing Figures SENSITIVITY PATENTEDJUH 6 I972 SHEET 10F 3CIRCUITS ELECTRONIC SENSITIVITY FIGI FIG. 3B

INVENTOR.

DAVID B. SPAULDI NG PATENTEDJUN 6 m2 SHEET 2 OF 3 O IOC o-/Ob ELECTRONICSPECIAL MESSAGE CIRCUITS ROUTE NEXT N0. EXIT E] E] ELECTRONIC CIRCUITSAND DISPLAY 0K( )FAST- DISPLAY PANEL FIG. 5

INVENTOR.

DAVID B. SPAULDING BY I 02214194 PATENTEIJJUII 6 I972 3. 668 624 SHEET30F 3 I 56 START g 48 .DETEGToR /8b 5 FF 46 "I" 52 DETECTOR I AIvIP oRDELAY COIL "on 5 5O DETECTOR 58 GLEAR II SHIFT RIGHT 2 TL BITACCUMULATOR CHECK GouNTER 66 G2 I I j I I PARALLEL GATE CHECK ANDCONTROL LoGIG I l 64 l woRKING REGISTER (n BITS) $8 SYSTEM RESET I I I II FIG. 6

GoNvERSIoN LOGIC AND DECODER 70.

44 I 4 1 EXIT ROUTE DIR. SPEG. @l LE Lil 1;]

DISPLAY INVENTOR.

DAvID B. SPAuLDING METHOD AND APPARATUS FOR VEHICLE CONTROL AND GUIDANCEBACKGROUND OF THE INVENTION This invention relates to vehicle guidanceand control systems in general and, more particularly, to a method andapparatus for vehicle guidance and control utilizing discrete,permanently magnetized marker elements.

The recent emphasis on automotive safety has pointed out the need for arelatively simple and inexpensive vehicle guidance and control systemwhich can be installed on existing highways. Automotive safety, itself,is a complicated composite of a number of interrelated variablescovering both human and environmental factors. In many instances, theenvironmental factors, such as, highway design and configuration, mustbe viewed as unchangeable with respect to automotive safety systemsbecause of the cost considerations involved in restructuring the highwayenvironment. This constraint defines certain parameters of the desiredautomotive safety system. The system should provide the vehicle operatorwith information concerning the speed and direction of movement of thevehicle with respect to an established vehicular lane in the highway. Ata minimum, a warning signal should be given to the driver whenever hedrifts from the desired lane either unintentionally or intentionally,but without signalling for a lane change. Ideally, full automoticcontrol of speed and steering should be available to the vehicleoperator. In addition, the system should be able to transmit informationto the driver concerning highway conditions, exit information, etc.

Given these performance parameters, the system must also be feasiblefrom a cost standpoint both for new highways and for retrofittingexisting highways. Various systems have been proposed in the past usingburied cables, metal elements, radioactive markers, inductive loops, andpassive reflectors. See for example, U.S. Pat. Nos. 1,981,206;2,317,400; 2,339,291; 2,750,583; 3,008,532; 3,149,691; 3,169,598;3,198,279; and 3,229,660. Although these prior art systems providedspeed and steering information to the vehicle, they were generally tooexpensive and complicated to be considered as feasible for aretrofitting installation in the extensive existing highway system.

It is accordingly a general object of the present invention to provide avehicle guidance and control system that is compatible with existing aswell as new highways.

It is a specific object of the invention to provide such a system inwhich the path defining highway markers can be installed rapidly andinexpensively.

It is another object of the invention to provide a vehicle guidance andcontrol system in which the information provided by the highway markerscan be updated without requiring removal of the markers.

It is still another object of the invention to provide a fully automaticvehicle guidance system.

These objects are accomplished in the preferred embodiment of theinvention by installing a plurality of spaced, permanently magnetizedelements in the roadway. The magnetized elements define a predeterminedpath or vehicular lane boundary. Vehicle mounted sensors respond to themagnetic fields of the marker elements and produce an electrical signalwhenever the vehicle reaches a preselected proximity threshold withrespect to the magnetic fence lane boundary. The resulting electricalsignal can be used for warning or steering control. Preferably, thepermanently magnetized elements are in the form of longitudinal pinswhich are explosively driven into the roadway. This arrangement pemiitsthe markers to be installed in new as well as existing highways at arelatively low cost. By varying the pattern of magnetic polarization ofthe discrete, permanently magnetized elements, binary information can betransferred to the moving vehicle. The system, in its fullconfiguration, provides for data processing in the vehicle to give thedriver a visual display in alphanumeric form of the desired highwayinformation.

The objects and features of the invention will best be understood from adetailed description of a preferred embodiment, selected for purposes ofillustration, and shown in the accompanying drawings in which:

FIG. 1 is a plan view in diagrammatic form of a highway and a vehicleshowing the permanently magnetized marker elements and vehicle mountedmagnetic field sensors of the present invention;

FIG. 2A is a view in cross section showing one of the permanentlymagnetized marker pins embedded in a concrete highway;

FIG. 2B is a plan view of the marker pin shown in FIG. 2A;

FIG. 3A is a view in cross section of another embodiment of thepermanently magnetized marker element showing a planar magnet and a pinfastener embedded in the concrete highway;

FIG. 3B is a plan view of the marker and fastener shown in FIG. 3A;

FIG. 4 is a plan view in diagrammatic form of a highway and a vehicleillustrating the arrangement of the magnetized elements for providingspeed information;

FIG. 5 is a plan view in diagrammatic form of a highway and a vehicleshowing the configuration of the magnetized elements for providing datatransfer to the vehicle; and

FIG. 6 is a block diagram of the processing circuitry for displaying theinformation obtained from the pattern of magnetic elements illustratedin FIG. 5.

Turning now to the drawings and particularly to FIG. 1 thereof, there isshown in diagrammatic form a vehicle guidance and control systemconstructed in accordance with the present invention. Two basic,interactive components make up the system. Permanently magnetized steelpins 10 are one element and electronic detection-processing circuits, indicated generally by the reference numeral 12, are the other. Themagnetized pins 10, which are similar in size and shape to commonly usedconcrete nails, are driven into a highway or roadway 14 in rows alonglane boundaries. Typically, the magnetized pins are installed on or nearexisting painted lane markers 16. The pins, being permanentlymagnetized, create around themselves a magnetic field that whenintercepted by a moving vehicle mounted coil 18, causes a voltage to beinduced in the coil. This signal voltage is amplified to a useful levelby conventional amplifier circuits 20 and is used to produce anaudio-visual indication on left and right alarms 22 and 24,respectively.

Given this simple system, a properly equiped vehicle 26 moving over arow of the permanently magnetized signal pins 10 picks up a series ofvoltage pulses that are converted into a corresponding series of beepsor light flashes. Each beep or tone corresponds to the crossing of asignal pin. Since the range of the pins magnetic field is sharplylimited, no pickup will occur as the vehicle moves away from directproximity with the pin row. The proximity threshold of the pickup coil18 to the magnetic pins 10 can be adjusted for the desired distance bymeans of a sensitivity control 28 which biases the amplifier 20.

It will be appreciated that two parallel rows of the magnetized pins 10inserted into the roadway 14 along existing painted line lane boundaries16 and spaced at a reasonable distance apart, such as, for example 5 to10 feet, can function as a magnetic fence. In the system shown in FIG.1, the vehicles turn signal 30 is connected to the pickup coil signalamplification circuit 20 so that the turn signal 30 will inhibit thelane warning alarms 22 and 24 whenever the turn signal is actuated. Thelogic function is obtained by inputting the turn signal and theamplified pin signals to an exclusive OR circuit (not shown) which gatesthe alarm signals 22 and 24. Thus, if a motorist attempts to cross alane boundary without using the turn signal 30, and thus temporarilydisabling the lane warning alarms, he will be immediately andcontinuously warned that his vehicle is not oriented properly in thelane.

One rather obvious value of this vehicle control arrangement is thatdaydreaming or physically sleepy drivers will be dependably warned ifthey begin to drift unconsciously across lane boundaries. When connectedwith the existing turn signals that are now incorporated in all newvehicles, the control system will strongly encourage disciplined use ofthe turn signal mechanism. Failure to do so will instantly alert thenegligent operator that he is not operating his vehicle properly. Thecontrol-alarm system will also provide considerable assistance to thedriver during snow or rain storms when the conventional painted lanemarkers are not visible.

In the preceding brief description of the basic concept of theinvention, the term roadway" has been used in its conventional sense asa way or path for wheeled vehicles, such as, cars, trucks, buses and thelike. However, since the present invention is not limited to thisparticular application, the term roadway" as used herein in thedescription and claims shall mean any substantially planar surface uponwhich a vehicle can travel. In this contest, it can be seen that thebasic magnetic pin guidance system can be used on such other diverseareas as airport runways and snow covered land and ice and in industrialwarehouses and manufacturing plants for the conveyance of goods along apredetermined path.

The basic system of a plurality of path defining permanently magnetizedelements located along the roadway at spaced intervals, vehicle mountedsensors which respond to the magnetic fields of the pins to produce anelectrical signal and some utilization means responsive to theelectrical signals can be implemented in a variety of ways. Thepermanently magnetized element 10, for example, can comprise explosivelydriven, longitudinal pins having a driving end and a driven end. Theconfiguration of such pins resembles the well-known concrete nails orfasteners. Representative examples of such fasteners are sold by theWinchester-Western Division of Olin Mathieson Chemical Corporation underthe trademark RAMSET fastening systems. FIGS. 2A and 2B illustrate theuse of a magnetized steel pin which has been driven into a concretehighway. Preferably, the driven end of the magnetized pin 10 should beat least flush with the surface of the highway 14. An alternativeconfiguration for the magnetized elements 10 is depicted in FIGS. 3A and3B. In this embodiment, a planar magnet 32 is surface mounted on thehighway by means of an explosive driven fastener 34 which extendsthrough an aperture in the magnet and down into the highway material. Itshould be understood that the present invention is not limited to thetwo preceding examples of the magnetized elements and fastening meansand that other arrangements can be used, such as, adhesive attachment ofplanar magnets to the surface of the highway.

It will be appreciated at this point in the description of the inventionthat the benefits and related advantages of the control system describedin connection with FIG. 1 can be achieved by a relatively simpleelectronic package; for instance, something comparable in complexity toa small transistor radio. However, by going to more involvedelectronics, it is entirely feasible to provide a broad range of othervehicle control functions. These additional operating modes are largelyinterdependent and can be added to the basic system as desired. FIGS. 4,5 and 6 illustrate some of these other operating modes.

Looking at FIG. 4, there is shown in plan view in diagrammatic form theconfiguration of the control system for providing speed control. Speedcontrol is a natural concomitant of the basic system. This type ofcontrol is achieve by using a separate control row of magnetizedelements 10 in which the pin-to-pin spacing is in direct ratio to thespeed limits for the particular highway location. It can be seen in FIG.4 that the spacing between pins 10a and 10b is less than the spacingbetween pins 100 and 10d. Changing the distance between the magnetizedpins correspondingly changes the pickup frequency at a constant vehiclespeed. The frequency of the induced voltage pulses can be directly usedto signal the driver of either an underspeed or over-speed operation.Conventional frequency responsive circuits 36 drive the appropriatespeed condition signals 38. With this particular pin spacingconfiguration, it is possible to smoothly taper speed limits from onelevel to another in a manner determined to optimum trafiic flow. It isalso possible, of course, to provide a direct readout of vehicle speedon a frequency responsive speedometer 40, if the pin spacing is heldconstant. A separate row of pins can be used for this purpose or thespeed pickup coil 18a can detect the magnetic fields of the laneboundary magnetized pins shown in FIG. 1.

The permanently magnetized elements or pins I0 can also perform otherfunctions. One such specific task is the storage of binary codedinformation in a manner which allows direct message transfer from theroadway 14 to the vehicle 26. The information transfer function can bereadily implemented because the pins can be magnetized in either of twodirections and s0 provide the two state signal needed to store andconvey digital messages. Looking at FIG. 5, the information transferfunction of the present invention is illustrated in plan view indiagrammatic form. The magnetic pins 10 are arranged in a predeterminedpattern of magnetic polarization. The two polarity states areillustrated in FIG. 5 by an open circle pin 1(le and a crossed circlepin 10f. Through suitable electronic processing in conventionalcircuits, indicated in block form in FIG. 5 by the reference numeral 42,the binary information is decoded into alphanumeric information which ispresented in visual form on a display pannel 44.

The elecu'onic processing system for the information transfer functionof the present invention is illustrated in block diagram form in FIG. 6.The vehicle mounted pickup coil 18b produces a voltage whenever a pickupcoil passes one of the magnetized pins 10. The polarity of the inducedvoltage is a function of the magnetic polarization of the pin. The pininduced signal voltage is amplified by amplifier 46 and applied to theinputs of l and O Detectors 48 and 50, respectively. An OR gate 52responds to either the occurrence of a 0 or 1 (eg. a pin passing) andits output is fed to a flip flop (FF) 54, a Start Detector 56, and aDelay circuit 58.

The Start Detector 56 has a second input from the l Detector 48. Thiscircuit configuration permits the Start Detector to recognize apredetermined start sequence. The start sequence interpreted by theStart Detector clears the circuit and the readout by setting FF 54 to aclear state which in turn clears all of the registering circuits. Inthis manner, the data displayed from the last sequence remains on thedisplay 44 until new binary information is transferred to the vehiclefrom a new set of magnetized pins.

After being cleared, an n-bit Accumulator 60 is set to receive the databits. If the data bit is a 0 no input is necessary since there is a O onthe input or first bit of the accumulator. The l Detector 48 is,however, connected to the input bit of the Accumulator 60 to set it to aI when a l is detected.

As the 1's or Os from the pickup coil 18b appear at the input or firstbit circuit of the n-bit Accumulator 60, they are entered in theaccumulator. After a short delay produced by Delay circuit 58, thecontents of the Accumulator are shifted one bit circuit to the rightleaving the input bit circuit empty or 0 to receive the next 0 or I. Thedelay provided by the delay circuit is less than the time required forthe vehicle to transit one pin interval.

A Check Counter 62 counts the number of pins and when n pins have beenpassed (or a preset number of pins), a Check and Control Logic circuit64 is actuated. The Check and Control Logic circuit energizes ParallelGates 66 to transfer the count in n-bit Accumulator 60 to a Working nbit Register 68. The binary data in register 68 is then decoded byDecoder 70 and displayed in alphanumeric form on the display 44.

With the control capabilities discussed above, it is possible to providean integrated full guidance system. Referring back to FIG. 1, thelateral warning signals developed by left and right hand pickup coilsI8, identified as Coil L and Coil R, respectively, can be used ascontrol signals for a steering servo system, indicated generally by thereference numeral 72. Speed control can be obtained by employing thefrequency responsive circuits 36 to provide a control signal for a servoactuated throttle linkage (not shown).

Having described the vehicle guidance and control system, it will beappreciated that the permanently magnetized pins have a number ofimportant advantages. In situations where the equipment is installedoutside and subjected to weather conditions of every kind and where theabuse of heavy traffic and even vandalism is to expected, the questionof maintenance is most important. In this respect, the magnetic pin hasmuch to ofier:

a. it is passive and required no power to operate;

b. The pins can be quickly inserted and have removal forces of severalthousand pounds;

c. When modifications of the patterns of magnetic polarization arerequired, the pins can be re-magnetized by one man with a single tool ifthe numbers are moderate;

d. The pins constitute a highly redundant system that does not loseeffectiveness if some pins are missing or have become neturalized;

e. Magnetic pins are compatible with other highway instrumentation;

f. The pins can be magnetized either before or after installatron;

g. The system can be conveniently implemented in local areas as needed.

These features of the vehicle guidance and control system can beobtained at relatively low cost per mile of highway instrumentation forboth new and existing highways.

What I claim is:

1. A system for providing information concerning the movement of avehicle with respect to a roadway path comprising:

a plurality of path defining permanently magnetized elements disposed inspaced relation along the roadway, said magnetized elements comprisinglongitudinal pins each having a driving end and a driven end, said pinsbeing driven into the roadway in a vertical position with the driven endof the pins being at least substantially flush with the surface of theroadway; and,

vehicle mounted means responsive to the magnetic fields of saidmagnetized elements for producing an electrical signal each time thevehicle passes one of said elements.

2. The system of claim 1 wherein said pins are explosively driven intothe roadway.

3. A method for defining a vehicular boundary in a roadway comprisingthe steps of:

a. driving a plurality of permanently magnetizable longitudinal pinsinto the roadway at spaced intervals along the path of the desiredvehicular boundary, said longitudinal pins each having a driving end anda driven end and being driven into the roadway in a vertical positionuntil the driven end is at least substantially flush with the surface ofroadway; and,

b. permanently magnetizing said longitudinal pins.

4. A method for defining a vehicular boundary in a roadway comprisingthe steps of:

a. permanently magnetizing a plurality of longitudinal pins,

said pins each having a driving end and a driven end; and,

b. driving a plurality of said magnetized longitudinal pins into theroadway at spaced intervals along the path of the desired vehicularboundary in a vertical position until the driven end of each pin is atleast substantially flush with the surface of the roadway.

5. A system for providing infonnation concerning movement of a vehiclewith respect to a roadway vehicular lane comprising:

a plurality of path vehicular lane defining permanently magnetizedelements disposed in spaced relation along the roadway with saidmagnetized elements forming the left and right hand magnetic boundariesof said vehicular lane, and said magnetized elements comprisinglongitudinal pins each having a driving end and a driven end, said pinsbeing driven into the roadway in a vertical position with the driven endof the pins being at least substantially flush with the surface of theroadway; and, vehicle mounted means responsive to the magnetic fields ofsaid magnetized elements for producing an electrical signal representingthe direction of movement of the vehicle with respect to the vehicularlane defined by said elements.

6. The vehicle system of claim 5 further characterized by:

the electrical signal produced by said vehicle mounted means having asignal characteristic which represents the position of said vehicle withrespect to the left and right hand magnetic lane boundaries; and,

means responsive to said electrical signal for steering the vehiclebetween said lane boundaries.

7. A roadway lane boundary alarm system for moving vehicles comprising:

a plurality of permanently magnetized elements disposed in linear,spaced relation along the roadway, said elements defining a vehicularlane boundary and comprising longitudinal pins each having a driving endand a driven end, said pins being driven into the roadway in a verticalposition with the driven end of the pins being at least substantiallyflush with the surface of the roadway;

vehicle mounted means responsive to the magnetic fields of saidmagnetized elements for producing an electrical signal whenever thevehicle reaches a proximity threshold with respect to said laneboundary; and,

means responsive to said electrical signal for producing an alarmsignal.

8. The vehicle lane boundary alarm system of claim 7 furthercharacterized by the proximity threshold of said vehicle mountedelectrical signal producing means being adjustable.

9, A system for providing information concerning the movement of avehicle with respect to a roadway path comprising:

a plurality of path defining permanently magnetized, substantiallyplanar elements disposed in spaced relation along the roadway, saidplanar elements each having a central aperture and being secured to saidroadway by means of a driven fastener extending through said apertureand into said roadway; and,

vehicle mounted means responsive to the magnetic fields of saidmagnetized elements for producing an electrical signal each time thevehicle passes one of said elements.

1. A system for providing information concerning the movement of avehicle with respect to a roadway path comprising: a plurality of pathdefining permanently magnetized elements disposed in spaced relationalong the roadway, said magnetized elements comprising longitudinal pinseach having a driving end and a driven end, said pins being driven intothe roadway in a vertical position with the driven end of the pins beingat least substantially flush with the surface of the roadway; and,vehicle mounted means responsive to the magnetic fields of saidmagnetized elements for producing an electrical signal each time thevehicle passes one of said elements.
 2. The system of claim 1 whereinsaid pins are explosively driven into the roadway.
 3. A method fordefining a vehicular boundary in a roadway comprising the steps of: a.driving a plurality of permanently magnetizable longitudinal pins intothe roadway at spaced intervals along the path of the desired vehicularboundary, said longitudinal pins each having a driving end and a drivenend and being driven into the roadway in a vertical position until thedriven end is at least substantially flush with the surface of roadway;and, b. permanently magnetizing said longitudinal pins.
 4. A method fordefining a vehicular boundary in a roadway comprising the steps of: a.permanently magnetizing a plurality of longitudinal pins, said pins eachhaving a driving end and a driven end; and, b. driving a plurality ofsaid magnetized longitudinal pins into the roadway at spaced intervalsalong the path of the desired vehicular boundary in a vertical positionuntil the driven end of each pin is at least substantially flush withthe surface of the roadway.
 5. A system for providing informationconcerning movement of a vehicle with respect to a roadway vehicularlane comprising: a plurality of path vehicular lane defining permanentlymagnetized elements disposed in spaced relation along the roadway withsaid magnetized elements forming the left and right hand magneticboundaries of said vehicular lane, and said magnetized elementscomprising longitudinal pins each having a driving end and a driven end,said pins being driven into the roadway in a vertical position with thedriven end of the pins being at least substantially flush with thesurface of the roadway; and, vehicle mounted means responsive to themagnetic fields of said magnetized elements for producing an electricalsignal representing the direction of movement of the vehicle withrespect to the vehicular lane defined by said elements.
 6. The vehiclesystem of claim 5 further characterized by: the electrical signalproduced by said vehicle mounted means having a signal characteristicwhich represents the position of said vehicle with respect to the leftand right hand magnetic lane boundaries; and, means responsive to saidelectrical signal for steering the vehicle between said lane boundaries.7. A roadway lane boundary alarm system for moving vehicles comprising:a plurality of permanently magnetized elements disposed in linear,spaced relation along the roadway, said elements defining a vehicularlane boundary and comprising longitudinal pins each having a driving endand a driven end, said pins being driven into the roadway in a verticalposition with the driven end of the pins being at least substantiallyflush with the surface of the roadway; vehicle mounted means responsiveto the magnetic fields of said magnetized elements for producing anelectrical signal whenever the vehicle reaches a proximity thresholdwith respect to said lane boundary; and, means responsive to saidelectrical signal for producing an alarm signal.
 8. The vehicle laneboundary alarM system of claim 7 further characterized by the proximitythreshold of said vehicle mounted electrical signal producing meansbeing adjustable.
 9. A system for providing information concerning themovement of a vehicle with respect to a roadway path comprising: aplurality of path defining permanently magnetized, substantially planarelements disposed in spaced relation along the roadway, said planarelements each having a central aperture and being secured to saidroadway by means of a driven fastener extending through said apertureand into said roadway; and, vehicle mounted means responsive to themagnetic fields of said magnetized elements for producing an electricalsignal each time the vehicle passes one of said elements.